Many different types of yard equipment are powered by small internal combustion engines that have manual recoil starters. For example, lawnmowers, chainsaws, compressors, generators, and tillers usually come equipped with a manual recoil starter. Although some of these machines also come equipped with built-in electric power starters, such as those found on larger riding lawnmowers, the manual recoil starter is a popular starter for small internal combustion engines.
To start a mower with a manual recoil starter the user initially pulls on a handgrip attached to a starter cord wound around a “one-way,” or overrunning, crankshaft. When the user pulls on the cord with enough force, it causes the crankshaft to rotate fast enough to trigger the ignition system. Typically, small machines with manual recoil starters have some sort of retraction mechanism to retract the cord after the user has pulled it. Although manual recoil starters are lighter and simpler than built-in electrical starters, they can pose many problems.
Users who lack the strength to pull the starter cord with sufficient force to turn the engine over, such as disabled persons, cannot start their machines with a manual recoil starter. Further, even users with sufficient strength often lack the balance to pull recoil starters in some machines which might simultaneously require pulling the starter with one hand and operating a trigger mechanism with the other. Finally, many users might be capable of using manual recoil starters but nevertheless find them hard to pull and irritating.
Some prior devices have attempted to improve starting technology for small gas-powered engines by directly attaching electric drill-type devices to the engine's flywheel, crankshaft, or power drive. U.S. Pat. No. 3,596,647 discloses an apparatus that connects an electric drill to the flywheel, crankshaft, or power drive of an engine without disrupting the hand starter mechanism. Similarly, U.S. Pat. No. 4,615,311 discloses a combined manual and power starting device for a gasoline engine that operates by directly rotating the crankshaft of the engine.
Attaching an electric drill directly to a crankshaft requires modifying the engine to accommodate the new starting device. Such a modification might at the very least void any warranty on the originally sold machine, as well as be expensive.
Other known starters pull the engine's starter cord by utilizing a pulley housed within a bulky frame. U.S. Pat. No. 3,718,129 discloses an apparatus comprising a base frame with a motor-driven pulley on one end, a long track that extends out to the engine, and a gripping structure that grips the starter cord. U.S. Pat. No. 5,285,693 similarly discloses an auxiliary starting device with a foundation base and support post that electrically pulls the starter cord.
These inventions are inconvenient for several reasons. Somebody operating a small machine, for instance a chainsaw, in a remote location, cannot easily transport a pulley in a heavy metal frame out to the machine in the event the engine shuts off or runs out of gas. In addition, these devices must be positioned on level ground to operate correctly, despite the fact that many machines with recoil starters are used for yard work in wooded or hilly areas. Finally, these machines require a large storage space and are therefore inconvenient to store.
Yet another prior shows a starting device that attempts to simplify the starting process without directly attaching a drill to the engine or requiring a large base frame. US published application No. 2004/0244754 A1 to Smith discloses a lawnmower with a pull rope that extends from the engine and is wound onto a pulley, which is releasably engageable with the motor. In the preferred embodiment, both the pulley and the starting motor are mounted to a pair of cross bars on the handle of the lawn mower.
Attaching an electrically powered starter motor and pulley system to the handlebars of a push mower creates an unnecessary weight on the handlebars. Further, this invention does not offer much help to somebody struggling to start a device that lacks handlebars, such as a weedwacker, chain saw or generator.